Blog

Why is repeatability important in scientific experiments?

A group of different species living in the same area is called a:

14. (WCSU25.[x], 9 points) Draw the Lewis structures of the following molecule/ion. a. BH3 b. COCl2 c. SO42-   Enter the total number of lone pairs in all structures (a+b+c) below.

Put the following steps of prokaryotic transcription in order.

Put the following steps of DNA replication of the leading stand in chronological order.

(WCSU25) Fill in the following table with the appropriate number of protons, neutrons, and electrons (enter a number only).     Protons Neutrons Electrons 48Ti+4 [blank1] [blank2] [blank3] 35Cl- [blank4] [blank5] [blank6]

List two differences between how prokaryotes and eukaryotes go through transcription and translation.

18.  (WCSU25.[x]) Ice cream begins as a solution of milk, sugar, and stabilizers. This liquid mixture is pasteurized at high temperature (72 oC) to kill any harmful bacteria. The pasteurized solution is cooled, flavors are added, and then it is placed in a “hardening room” (at -38 oC) to freeze.   Cs (solid) = 3.10 J/g·K Cs (liquid) = 1.60 J/g·K ΔHfus = 186 J/g a. (5 points) Draw the cooling curve for ice cream beginning as a liquid at 72 oC to solid at -38 oC. The freezing point of ice cream is -3 oC.  Label the axes with temperature values. (Blank graph given below.))   b.  (8 points) Calculate how much heat (in kJ) must be removed from a ½ gallon (912 g) of Bittersweet Mint when it cools from 72 oC to -38 oC.   Enter the heat lost from the ice cream below:

23. (WCSU25.[x], 6 points) The balanced combustion reaction for methane is shown. CH4 (g)       +       2 O2 (g) 

How did MDMA become popular and openly used in the late 70’s and early 80’s?